“Edema” is the accumulation of excess fluid in a fluid compartment. This accumulation can occur in the cells (i.e., cellular edema), in the intercellular spaces within tissue (i.e., interstitial edema), or in other spaces in the body. Edema can be caused by a variety of factors, including indications associated with osmotic pressure, such as hypotonic fluid overload, which allows the movement of water into the intracellular space, or hypoproteinemia, which decreases the concentration of plasma proteins and permits the passage of fluid out of the blood vessels in to the tissue spaces. Other factors can include poor lymphatic drainage (known as “lymphedema”), conditions associated with an increased capillary pressure (e.g., excessive retention of salt and/or water), heart failure, and conditions associated with increased capillary pressure, such as inflammation.
When a person is symptomatic of edema, early diagnosis and treatment is imperative. As swelling increases, more pressure is exerted on surrounding cells, tissues and blood vessels. As these areas are squeezed from the increase of fluid and from the natural body response to increased inflammation (as a component of “first response” to an injury), more tissues die, more fluids are released, and the amount of edema presented increases. As edema increases, there is more potential for this “cascade effect” to continue, to result in even more damage. Thus, early diagnosis and regular patient monitoring can be critical to identify swelling occurring prior to the generation of the “edema cascade.”
Compression garments can be used to prevent and or treat edema and a number of conditions that cause swelling in patient body parts or body areas. In this regard, edema, which as indicated, presents as excessive interstitial fluid accumulation, may arise from a variety of illnesses and conditions, including venous valvular insufficiency, post-phlebotic syndrome, posttraumatic swelling, postoperative swelling, congestive heart failure-related swelling, hypoalbuminemia-related swelling, drug induced swelling, and lymphedema
In the treatment of edema-like conditions, compression garments can address patient body part or body area swelling by increasing transport and reducing stagnation of interstitial fluids. Such interstitial fluids operate to increase nutrient delivery to tissue, remove waste from tissues, reduce pain from swelling, and decrease the risk of infection.
In addition to therapeutic effectiveness, compression garments are an increasingly popular clothing item worn by athletes and active individuals with the goal of enhancing recovery from exercise. While the actual mechanism of action for compression clothing remains largely unknown today, it is generally hypothesized that when compression garments are used during recovery, muscle swelling is reduced. Improvements in recovery after exercise are seen by both men and women, who can be well-trained athletes or “weekend warriors.” Generally, it seems likely that compression garments display greater overall benefits following higher amounts of, or greater intensities of, exercise. Notwithstanding the lack of clear knowledge about how compression garments assist in athletic recovery, it is nonetheless important to provide persons in need of treatment with compression garments that fit well.
For therapeutic use, proper fitting of compression garments is important if only because ill-fitting garments will not provide the intended/prescribed amount of compression therapy to the person being treated. Existing methods of fitting compression garments for a specific patient are problematic, however. As would be understood, human body parts or body areas that may be fitted with compression garments are not regularly shaped, and some may be quite complex in surface shape or morphology, such as in patients with advanced lymphedema or those who are morbidly obese, for example.
A further concern in the design of a compression garment is patient comfort. A compression garment may provide proper compression characteristics, but if the wearer experiences discomfort due to pinching, chaffing, buckling, or other reasons, she is unlikely to be compliant in wearing the compression garment and, thus, may not achieve therapeutic benefits. For example, the noncompliance rate for graduated compression stockings has been reported to be 30%-65%. Commonly cited reasons include, among other things, pain, discomfort, difficulty donning the stockings, perceived ineffectiveness, excessive heat, and skin irritation. Of course, if a patient fails to wear a compression garment that is prescribed for a potentially chronic or already chronic condition, that condition can become worse and, perhaps, irreversible damage could result. Thus, improved patient compression garment compliance is a need today.
The compression garment must be able to apply the intended/prescribed compression levels and compression gradients for each area of an affected body part. The proper compression gradients must be applied in the proper direction (or “vectors”). In other words, in use, a compression garment must have the properties of good fit and appropriate therapeutic compression gradient values to effectively provide the intended/prescribed level of compression therapy to a person in need thereof, as well as to prevent harm from occurring to the patient caused by a poorly fitting garment.
Given the vast variation in human body shapes, custom garments can be indicated to provide optimum therapeutic benefits. Traditionally, compression garment fitting has been conducted primarily by use of a tape measure. While tape measurement techniques are widely available to a broad scope of medical providers, the technique generally suffers from poor accuracy. In short, tape measurement is not a very effective garment measurement tool because the technique has been shown to exhibit as much as an about 8 to about 12% inaccuracy due to inter and intra-operator variability. Such variability gives rise to a need for methods of measurement that demonstrate improvements in both accuracy and precision.
In therapeutic settings, patients often receive a recommendation for a custom fit garment, even though a custom fit garment is often far more expensive than an off-the-shelf compression garment. The time needed to generate such custom fit garments is long: the patient must be measured by a trained technician, and such measurements must be forwarded to a garment manufacturer, before the garments can be placed in a queue for manufacturing.
As noted, the current methodology used to fit compression garments is often inaccurate. Thus, using current fitting methodology, even expensive custom fit garments may not fit properly even when they are new. This means that, once the garments are sent back from the manufacturer, the fit quality must be checked by the technician and/or medical provider to make sure that the fit is therapeutically correct, thus necessitating further delays and increased cost in ensuring proper patient treatment. Often these custom-made compression garments must be remade; the fit error rate has been estimated to be from about 15 to about 40%. For chronic conditions, such as lymphedema or diabetic limb indications, such delay can cause irreversible harm to the patient. As a general rule, compression garments are usually only guaranteed to be effective for a life of six months, this cycle must be repeated regularly, which can reduce patient compliance, as well as greatly adding to the cost of treatment given the high amount of in-person time a patient requires to ensure proper fit of the compression garment.
For off-the-shelf compression garments, a person is often left with insufficient information when trying to select the appropriate compression garment. Such off-the-shelf garments are generally selected using a manufacturer's sizing chart and starting pressure levels that are provided by manufacturers. Pressure ranges for such compression garments can apply to a given range of circumferences. This circumference range is often large, which may make it more difficult to understand the compression provided by the garment, especially beyond an initial distal measurement. An individual consumer may fit into several sizes or have parts of his or her arm that fit into different sizes. As a result, the user may end up with ill-fitting compression garments that, at best, provide limited benefits, and, at worst, can end up causing harm to the user. Nonetheless, such off-the-shelf garments remain the status quo for those seeking lower cost compression garments.
Further, even if a consumer or clinician has a compression chart with detailed compression gradient information for a particular compression garment design, the fitting of compression garments may still be problematic. It can be difficult to decide upon a size and compression class that will meet all specifications of a particular individual. For example, there may be multiple points on a patient where the garment must meet compression specifications. Specifications can require graduated compression gradient values, meaning that compression must vary by a given amount along the length of a limb, for example. Individuals may also have specific characteristics, such as compression sensitivity and varying degrees of swelling in various limb locations, muscle shape, etc., which can create even greater complexity in the selection process. The locations for such body part structural variations will necessarily be specific to the individual.
The true external shape of the body part or body area, called “morphology” herein, being fitted for compression garments will be difficult to reproduce using the standard compression garment fitting method of using a tape measure. Tape measures will only identify differences in body part morphology to the extent that a large number of external measurements are made. Since large variations in body part shape can be seen in short distances along the surface of a body part, the conventional tape measurement method cannot generate a shape for the body part or body area being fitted. As such, many custom fitted compression garments often do not provide the desired amount of compression along the whole of the body part or body area being treated with the compression garment. More recently, three-dimensional imaging of a body part or body area has been proposed, however, such methods have not been found to provide clinically accurate reproductions, as discussed in more detail hereinafter.
Still further, certain persons may be interested in obtaining garments that are specifically sized to fit their bodies. Such “custom-fit” garments have traditionally been available only from tailors or seamstresses, and have accordingly been quite expensive and therefore generally out of reach of the average clothing consumer. Yet further, the lack of regulated sizes in the clothing industry makes it difficult for a person to know whether a particular garment will fit her. This not only makes trying on clothes in a retail establishment time consuming for shoppers, but also makes purchase of clothing online particularly challenging.
There remains a need for improved methods of generating accurate shape information for a patient's body part or body area, where such shape information can be used to diagnose and monitor edema and other conditions in a patient. Still further, there remains a need for improvements in the fitting of compression garments for use by a specific patient in need of treatment with compression therapy. Yet further, there remains a need for compression garments that closely match the shape of the body part or body area being fitted with the compression garment. The present invention provides this and other benefits.